The objective of this research is to study the biochemical controls involved in the development and function of lung tissue. The main emphasis is given to the involvement of vitamin A in this process. Two newly discovered cellular binding proteins, one specific for retinol (vitamin A - alcohol), the other specific for retinoic acid (vitamin A - acid), are studied during perinatal development and maturation of lung tissue. The goal of these studies is to delineate the physiological stimuli which regulate the levels of these proteins in lung tissue.